Source total dissolved carbon

Fig. 3.23 Carbon isotopic composition of total dissolved carbon in some large river systems. Data source Amazon LongineUi and Edmond (1983), Rhine Buhl et al. (1991), St Lawrence Yang et al. (1996)...

The carbonate module in the present system compares values of the total dissolved carbonate concentrations from several sources to evaluate the internal consistency of data on the carbonate system. Three total carbonate concentrations may be available tdcl, the sum of the analyzed concentrations of dissolved CO2, bicarbonate and carbonate, tdc2, the analyzed total dissolved carbonate concentration, and tdc3, the value calculated from the analyzed pH and alkalinity by the geochemical modeling program. Differences among these three concentrations are used to decide the quality of the carbonate analytical data. 

Drinking water suppHed to carbonated soft drink manufacturing faciUties from private or municipal sources must comply with all regulatory requirements. Treated water must meet all U.S. Environmental Protection Agency primary maximum contaminant levels and may also be subject to additional state requirements. Treated water is routinely analyzed for taste, odor, appearance, chlorine, alkalinity, iron, pH, total dissolved soHds, hardness, and microbiological contamination. 

S Significant NS Not significant DOC Dissolved organic carbon TOC Total organic carbon Source [58]... 

During cell growth, dissolved organic carbon is excreted to the medium and is a source of reductant for chemically and biologically mediated reactions. The magnitude of this process is open to debate (Fogg, 1983 Sharp, 1984), but is likely to be on the order of 5-10% of the total phytoplankton carbon. 

A reviewer was concerned with the possible inclusion of carbonate carbon during oxalate formation. We cannot totally rule out a jfraction of the oxalate carbon arising from dissolved carbonate. But, limestone carbon cannot be the sole source of the oxalate carbon because of the C-14 content. The conversion of carbonate carbon to oxalate carbon would result in an oxalate radiocarbon age older than the true age and our conclusion that the accretion layer is not 30,000-40,000 years old would still be valid. Russ et al. (22, 22, 25) and Watchman et al. (26-28) obtained radiocarbon results that suggest oxalate does not contain " C-free carbon by the superposition of multiple oxalate and known age pictograph paint layers. Furthermore, the oxalate value of -11.67%o is closer to atmospheric (-7.8%o) than to marine carbonates ( 0 %o). 

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